1. Field of the Invention
This invention relates to building construction, and more particularly relates to a lifting apparatus and process for elevating a folding roof.
2. Description of the Invention
In modular building construction, building sections are typically prefabricated and interconnected at a factory and are transported to a site by common carriers such as: trailers, trucks, trains, etc. for erection. The common carriers travel on roadways or trackways that are governed by interstate and intrastate commerce regulations and laws.
Many of these laws and regulations are enacted to provide for safety and health during transportation by imposing limitations on: height, weight, size, and contents of material that the prefabricated building sections may comprise. In particular, regulations concerning height limitations have posed difficult problems for manufacturers in building and designing roofs with enough pitch for most commercial and residential purposes. For example, manufacturers find that it is almost impossible or extremely difficult to construct and interconnect a roof at the factory with a pitch and height which can be either transported on common carriers while complying with the laws regulating height, or be erected simply, quickly, and economically at their ultimate destination when the interconnected roof is transported at a pitch and height less than that required by its design.
An additional complication for manufacturers is the fact that if a roof is not attached to the construction during transport, environmental conditions such as: rain, snow, wind and extreme heat and cold may cause serious and undesirable damage to exposed parts of the construction normally protected from environmental conditions by the roof.
Earlier attempts to solve the above difficulties entailed transporting to the site of erection an inclined roof consisting of a lower fixed section and an upper section. The upper section is pivoted to the fixed section to swing between an operative erected position and a lower inclined transport position. Such a construction, however, necessitates a complex arrangement of uprights and rafters to support and elevate the roof, and also requires difficult and substantial fabrication procedures at the factory and at the site of the erection.
Another attempt teaches pivotally mounting a roof section at the center so that it may pivot and be swung into a horizontal position during transport. But this construction increases the overall width of the modular building at the roof when in a horizontal position. It also entails substantial construction at the site of erection and substantial accessories to support the roof in a transport position.
Thus, it is an object of this invention to provide modular building structures with a prefabricated roof that will meet both the commerce laws imposing height limitations on a pitch of the roof and provide adequate environmental protection during transportation by common carriers.
It is another object of this invention to provide a prefabricated roof for modular building structures that can be factory installed in a folded position and elevated to a final position at the site of erection with minimal construction and accessories.
It is still an object of this invention to provide simply constructed lifting bars for erecting prefabricated roofs for modular building structures from a height in compliance with commerce laws regulating the height of objects transported by common carriers to a greater height as required by design specifications for the structures.
It is still a further object of this invention to provide a hinge that substantially supports a prefabricated roof when initially folded but that does not substantially support the roof when unfolded and elevated to its final pitch and position.
It is still a further object of this invention to provide a process and apparatus for elevating folded prefabricated roofs in modular building structures at the site of erection to a desired pitch and position with minimum construction and accessories.